Traditionally, the handling of flowable materials and specifically dry particulate or granular materials has presented unique problems. For instance, these materials include chemicals, minerals, fertilizers, foodstuffs, grains, agricultural products and the like. Generally, such materials have been handled chiefly by two types of material handling systems. Where large quantities of material are required, specialized bulk handling equipment is used. For example, materials are loaded into a truck, railroad car or barge at the supply location and then transported to a place of unloading where the materials are transferred to a hopper or other storage device. The materials are distributed from this point to the actual destination sites. Since the materials are often exposed during at least part of the handling, there is always the possibility of damage or contamination.
In addition, various problems frequently arise relative to discharging the material from the container. Depending upon the material, interruption of the container unloading operation can result when the discharge means becomes clogged. This frequently occurs when shipping moist or compactible materials which tend to cake or bridge across the discharge opening. This problem has been alleviated in the prior art by using larger discharge openings. However, a large discharge opening often results in loss of control of the material discharged. Smaller discharge openings allow greater control but often require the time-consuming and therefore costly step of clearing blockages.
Prior art receptacles have involved various types of discharge spouts in an attempt to overcome these problems. However, the more involved the spout construction, the greater the cost and time to manufacture the receptacle. As disclosed in U.S. Pat. No. 4,143,796, a discharge spout is formed in the bottom of a material handling receptacle. The bottom is formed when two semi-circular pieces of identical construction are sewn together to allow a free edge in the center which is then bisected by a cut to define a cross-cut positioned centrally in the bottom panel. An opening is thus formed in the bottom by the flaps resulting from the bisecting cuts. A spout assembly is located in the center of the bottom panel and extends through the opening therein formed by the perpendicular cuts. The spout is then sewed at one end to the bottom panel of the receptacle with a single sew line. A closure flap is inserted within the opening beside the spout and sewn to the bottom. The triangular flaps formed from the bisecting cuts are folded over and sewn to form drawstring passageways.
With this construction, the spout is tied with a cord and then rolled up and inserted through the opening into the bottom of the receptacle. The closure flap is then tucked inside the flaps forming the opening and the drawstring, which is inserted in the passageways formed by the flaps being folded over and sewed, is then drawn tight to secure the receptacle opening and allow the receptacle to be filled with flowable materials.
This construction is efficient and performs its function well. However, it may require several time-consuming steps to sew the triangular flaps that form the drawstring passageways and to sew the flap cover and the discharge spout to the bottom panel of the receptacle. In addition, the single sew line fastening one end of the spout to the bottom of the bag (and the closure flap, if desired) may break or become stretched. If so, the tear may go slightly past the sew line and allow product leakage through the extended tears or may allow product to leak through the exposed or stretched needle holes.
The present invention provides an improved discharge spout construction which not only functions in an exceptional manner but also is economical and simple in construction. In this construction, at least three triangular flaps are formed in the bottom panel with intersecting cuts of predetermined length. These triangular flaps form an opening in the bottom panel when they are folded into the interior of the receptacle. A substantially cylindrical spout is formed of flexible material and a substantially circular shaped flap is formed for covering the opening. A double needle sewing machine is preferably used to simultaneously sew one end of each of the folded triangular flaps, only one side of the opening covering flap and one end of the pouring spout to the bottom panel and to each other with a common double threadline or sew line to simultaneously form drawstring passageways, a covering for the opening and the receptacle pouring spout.
When the receptacle is large in size and holds large quantities of material, the weight of the material, as it is forced by gravity out of the receptacle through the discharge spout, has a tendency to tear the outer ends of the intersecting cuts as explained previously in respect to the prior art.
In the present case, a reinforcing web encircles the opening beyond the outer ends of the intersecting cuts forming the triangular flaps and a double needle machine attaches the reinforcing web, the one side of the cover flap, the outer ends of the folded flaps and the one end of the pouring spout simultaneously to each other and to the bottom panel. The reinforcing web prevents tearing of the bottom panel at the outer end of the cuts which form the triangular flaps. When the flowable material is passing through the discharge spout from the receptacle, the reinforcing web prevents the force of the material against the spout from tearing the outer ends of the cuts which formed the triangular flaps. Using a double sew line is significant in this case where it might not normally be important. The reinforcing web with the double sew line eliminates the potential for sifting of product from a tear hole because the second sew line where the discharge hole and the bag bottom meet is 1/4 inch (the distance between the sew lines) away from where the tear is stopped by the other or first sew line on the reinforcing web. Thus a buffer area is created between the tear and the second sew line. If the first sew line breaks or stretches, the tear may move partially into the buffer area but will still be a slight distance away from the first sew line. Thus the web reinforcement not only reduces the tearing of the cuts but also provides a safety distance between sew lines which reduces product loss through tears or product sifting through exposed needle holes.
Intersecting cuts in the bottom panel of the receptacle can be used to form three triangular flaps. Two bisecting cuts can be utilized to form four triangular flaps and three or more intersecting cuts can be used to form six or more triangular flaps.